Lung Cancer Risk May Be Predicted by Frequency of COPD Exacerbations

A diagnosis of visual emphysema was significantly associated with a diagnosis of lung cancer in individuals with COPD.

Independent predictive factors of lung cancer in patients with chronic obstructive pulmonary disease (COPD) may include the severity of COPD, airflow obstruction, visual emphysema, and frequency of respiratory exacerbations, according to a study published by CHEST.

Researchers conducted a nested, case-control study that included individuals between 45 and 80 years of age, with or without a diagnosis of lung cancer, who were current or former smokers (≥10 pack-years), and who were currently participating in the COPDGene study with longitudinal follow-up for up to 8 years. Individuals diagnosed with lung cancer during follow-up (n=169) were matched 1:4 with 671 control participants not diagnosed with lung cancer.

Study results demonstrated an independent association with a diagnosis of lung cancer during the follow-up period in individuals with a lower body mass index, a more severe form of airway obstruction (odds ratio [OR], 1.28 per 10% decrease; 95% CI, 1.12-1.46; P <.001), and visual emphysema (OR, 2.31; 95% CI, 1.41-3.76; P <.001), in addition to a higher number of acute respiratory exacerbations (per event increase, OR, 1.39 0, 1, ≥2; 95% CI, 1.04-1.85, P =.02) in the year before enrollment.

Visual emphysema, an increase in airway wall thickness, and current use of corticosteroids as single therapy were found to be the highest predictors for a diagnosis of lung cancer (OR, 1.21 [95% CI, 1.14-1.28; P <.001]; OR, 1.45 [95% CI, 1.16-1.81; P <.001]; and OR, 1.29 [95% CI, 1.17-1.41; P <.001]; respectively). Compared with individuals without a reported respiratory exacerbation, individuals with 1 or more exacerbation incidents had a higher risk of developing lung cancer (hazard ratio [HR], 2.75; 95% CI, 1.59-4.75; P <.001). The diagnosis of visual emphysema was also significantly associated with the diagnosis of lung cancer (HR, 3.0, 95% CI, 1.98-4.59; P <.001), with individuals with moderate to confluent emphysema found to be at the highest risk (HR, 3.13 [95% CI, 1.59-6.35] and HR, 2.48 [95% CI, 1.12-5.57], respectively).

Researchers concluded that the severity of airflow obstruction was an independent risk factor for lung cancer in both individuals in the COPDGene cohort and those with COPD. In addition, visual evidence of emphysema was also associated with lung cancer, with higher risks associated with more severe disease. Finally, for the first time, researchers identified that the frequency of acute respiratory exacerbations also increased the risk for lung cancer, independent of both airflow obstruction and extent of emphysema.

Therefore, researchers suggested that clinicians consider including the assessment of visual emphysema and history of acute respiratory exacerbations, in addition to airflow obstruction, when screening for lung cancer in individuals with COPD.